Preheat oven to 325° F. Grease a 9-inch springform pan with butter and set aside.
Use a food processor to crush graham crackers until fine crumbs form. Add sugar and melted butter. Pulse a few times until combined. Transfer mixture to prepared pan and firmly press the mixture to the bottom of the pan. I like to use the bottom of a measuring cup to press the mixture down.
Bake crust for 10 minutes. Remove from oven and set aside to cool. Place springform pan on top of aluminum foil and wrap the outside of the pan tightly with the foil. Make sure the foil comes almost all the way up the sides of the pan. Prepare cheesecake mixture.
Cheesecake
In the bowl of a stand mixer, beat cream cheese and sugar on medium-high speed until smooth, about 4 minutes. Scrape down the sides and bottom of the bowl as necessary.
Add the sour cream, vanilla and lemon juice. Beat until combined, about 1 minute. Scrape down the sides and bottom of the bowl. Add the eggs and egg yolk, one at a time, beating just until combined after each addition. Avoid over-mixing. Transfer batter to springform pan with graham cracker crust. Prepare water bath.
Fill a roasting pan with hot tap water until 1 inch high. Place roasting pan in the oven and then place the cheesecake in the water-filled roasting pan.
Bake at 325° F for 60 minutes. The cheesecake is done when the pan is gently shaken and the center of the cake jiggles slightly, but the edges are set. Turn the oven off, prop the oven door open and keep the cheesecake in the water bath for 1 hour. Remove cake from water bath and transfer to the refrigerator to cool for 4 hours or overnight. Serve chilled and fresh fruit.
Strawberry Sauce
In a small bowl, stir together cornstarch, lemon juice and warm water until cornstarch is absorbed.
In a medium saucepan or pot over medium heat, add the cornstarch mixture, strawberries and sugar. Stir until strawberries are coated. Bring the mixture to a simmer and let it simmer for about 5 minutes. Stir occasionally.
Remove pot from heat and let the mixture cool in the pot to room temperature. The sauce will thicken as it cools. Slice cheesecake and serve slices with strawberry sauce.
Notes
How to store cheesecake: Store cheesecake covered and in the refrigerator for up to 3 days.How to freeze cheesecake: Let cheesecake chill in the refrigerator for at least 4 hours. Transfer cheesecake to a 9-inch cardboard circle or cut into quarters. Wrap cheesecake in plastic wrap, then aluminum foil. Freeze on a flat surface for up to 1 month. Defrost in the refrigerator before serving. Strawberry sauce: Use the sauce warm, at room temperature or chilled. If you store it in the refrigerator, heat it up in a saucepan before using to thin it out if desired.